Construction Development (Qatar)

This study develops a green, high-performance, cement-based grout by replacing manufactured sand with iron tailings sand (ITS) at ratios of 0–50% to address resource depletion. Fluidity, mechanical strength, and expansion rates were experimentally evaluated to determine engineering feasibility. The results indicate that while ITS inclusion reduces fluidity due to particle morphology, it significantly enhances compressive strength through a physical filling effect. Specifically, the 30% replacement group achieved a peak 28-day compressive strength of 100.4 MPa. Comprehensive analysis identifies 40% as the optimal replacement rate, where the grout strictly satisfies relevant industry specifications regarding fluidity, early strength, and volume stability. This research demonstrates the practical significance of utilizing industrial solid waste to produce high-performance sleeve grout for prefabricated construction.

In desert edge areas, the degree of soil salinization is high, and aeolian sand contains a significant amount of fines. As fine‐grained aeolian sand is more susceptible to temperature, moisture, and salt influences compared to pure aeolian sand, its use in road construction may induce roadbed diseases at later stages. To investigate the mechanical properties of fine‐grained salinized aeolian sand in seasonally frozen desert edges, laboratory triaxial unconsolidated undrained shear tests were performed on specimens with varying freeze‐thaw (FT) cycles (0–9 times), confining pressures (50–150 kPa), and fine contents (0%–16%). The study examined stress–strain relationships and shear strength variations in FT cycles. Additionally, scanning electron microscopy was employed to analyze microstructural changes in particle contact states before and after FT cycles. The concept of shear strength deterioration was introduced to quantify strength decay rates, and a predictive model incorporating both FT cycles and fines content was developed. Results indicate that stress–strain behavior shifts from strain softening to weak softening with increasing FT cycles, particularly at higher fines content. Shear strength declined hyperbolically with FT cycles and linearly with fines content, with a 34.4% reduction observed for 16% fines after 9 cycles. Microstructural analysis showed fines and salt crystals fill pores initially but degrade under FT, weakening particle bonds. The findings provide valuable references for road engineering construction in desert‐edge salinized aeolian sand regions.